• Analytical Science and Technology
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• v.17 no.5
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• pp.369-374
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• 2004

Plastic was decomposed with nitric acid after being carbonized by sulfuric acid. Then excess sulfuric acid and nitric acid was removed by evaporating and drying. Precipitated $SO{_4}^{-2}$ ion of $PbSO_4$ was resolved itself into $H_2S$ by HI in hydrochloric acid and was volatilized. Then $Pb^{+2}$ was dissolved and was measured by AAS and ICP. The test for reproducibility using PVC-Pb standard material (690-34610mg/kg) was conducted and the accuracy was more than 99.9% compared with the estimated concentration. The precision by AAS was 99.8% and that of ICP was 99.9%.

• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.88-99
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• 2017

This study investigated the clinical characteristics of the Internet addiction risk group using MMPI-2 and discussed whether the MMPI-2 can be used for diagnosis, evaluation and intervention of the Internet addiction risk group. We verified the difference in the MMPI-2 scales between the addiction-risk group and the general user group, and verified whether the substance-related scales MAC-R, AAP, and AAS scales can distinguish between Internet addiction risk group and general users. The results of the analysis of the MMPI-2 characteristics of 39 Internet addiction risk group and 21 general user group who visited internet addiction counseling center showed significant difference in the D, Pa, Pt, Sc, and Si scales on the clinical scale. There was no difference in the MAC-R, AAS, and APS scales between the Internet addiction group and the general user group. This suggests, that it is not possible to screen the Internet addiction risk group with the supplementary measure, and it is necessary to develop a new scale to diagnose internet addiction.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1720-1726
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• 2014

(S)-Alanine Racemase Chiral Analogue ((S)-ARCA) was used as an efficient adsorbent for the selective separation of D-amino acids (D-AAs), which are industrially important as chiral building blocks for the synthesis of pharmaceutical intermediates. The organic phase, containing (S)-ARCA adsorbent and phase transfer reagents, such as ionic liquid type molecules (Tetraphenylphosphonium chloride (TPPC), Octyltriphenylphosponium bromide (OTPPBr)), were coated on the surfaces of mesoporous carbon supports. For the immobilization of chiral adsorbents, meso/macroporous monolithic carbon (MMC), having bimodal pore structures with high surface areas and pore volumes, were fabricated. The separation of chiral AAs by adsorption onto the heterogeneous (S)-ARCA was performed using a continuous flow type packed bed reactor system. The effects of loading amount of ARCA on the support, the molar ratio of AA to ARCA, flow rates, and the type of phase transfer reagent (PTR) on the isolation yields and the optical purity of product D-AAs were investigated. D-AAs were selectively combined to (S)-ARCA through imine formation reaction in an aqueous basic solution of racemic D/L-AA. The (S)-ARCA coated MMC support showed a high selectivity, up to 95 ee%, for the separation of D-type phenylalanine, serine and tryptophan from racemic mixtures. The ionic liquids TPPC and OTPPBr exhibited superior properties to those of the ionic surfactant Cetyltrimethyl ammonium bromide (CTAB), as a PTR, showing constant optical purities of 95 ee%, with high isolation yields for five repeated reuses. The unique separation properties in this heterogeneous adsorption system should provide for an expansion of the applications of porous materials for commercial processes.

• Analytical Science and Technology
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• v.10 no.6
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• pp.395-402
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• 1997

The comparison study between EPA method 3050 and the test method offered by Ministry of Environment in Korea was performed to investigate a matrix effect on extraction. In this study, 12 inorganic priority pollutants(Cd, Cr, Cu, Pb, Ni, Zn, As, Sb, Se, Hg, Be, Tl) were spiked to the sludges and estuary sediment samples. The extracts were analyzed by AAS, HG-AAS, and ICP/MS. Results were discussed in terms of recoveries, relative standard deviations, and the method detection limits. Mean recovery of the elements except As, Sb, and Se was 93% when the procedure of EPA method was applied. The Korean extraction method, however. showed a significant matrix effect to give very poor recoveries.

• Journal of Veterinary Clinics
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• v.27 no.1
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• pp.29-34
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• 2010

To examine the attitude of students toward animals and its relation to veterinary ethical decision making, 302 pre-veterinary and veterinary students of three national universities (Seoul, Chungbuk and Kyungsang National University) were requested to answer the Animal Attitude Scale Test, an indicator of one's pro-animal attitude. A significant gender difference in the AAS scores was found with higher scores in females (female vs. male, 65.27 vs. 57.40; p < 0.0001). The students who have companion animals had higher AAS scores (62.55) than those who donot (58.03, p < 0.0001). However, years of study and experience with animal protection activities did not affect the AAS scores. The correlation between the attitude toward animals and ethical decision making was found in the investigation with two cases of a veterinary ethical dilemma: the medical treatment of a cow in its last gestation stage with ocular squamous cell carcinoma and the euthanizing of a 12 year-old dog with urinary incontinence. The students tend to support for veterinarians to influence clients' decisions in treatment by using their power as medical professionals, even if doing so could partly damage the interests of the clients or patients. The significant correlations between the AAS scores and veterinary ethical decision making were found in this study, which implies that the attitude toward animals should be considered as one of the major factors in making ethical decisions in veterinary practice.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.898-901
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• 2005

In this paper, we design an authorization policy module which provides the safty and reliable authorization of the user to provide the resolution for authorization in distributed environments. PKI have been utilized much by an information security-based structure for Internet electronic commerce, it is developing X.509-based in various application field such as a network security. Especially, it provides good resolution for the authentication of the user in the situation not to meet each other, but it is not enough to provide the resolution of the authorization in distributed computing environments. In this paper, We provide AAS model, which can be used distributed resources by distributed users, and design AAS model which is an authorization policy module in the Linux-based Apache Web server.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.237-254
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• 2021

Background: Some of the introduced alien species introduced settle, multiply, and spread to become invasive alien species (IAS) that threaten biodiversity. To prevent this, Korea and other countries legally designate and manage alien species that pose a risk to the environment. Moreover, 2160 alien species have been introduced in South Korea, of which 1826 animals and 334 plants are designated. The inflow of IAS can have negative effects such as ecosystem disturbance, habitat destruction, economic damage, and health damage to humans. To prevent damage caused by the inflow of IAS in advance, species that could potentially pose a risk to the environment if introduced in South Korea were designated as alert alien species (AAS). Results: The designation criteria were in accordance with the "Act on the Conservation and Use of Biological Diversity" and the "Regulations on the Ecological Risk Assessment of AAS and IAS" by the National Institute of Ecology. The analysis result of risk and damage cases indicated that mammals affect predation, competition, human economic activity, virus infection, and parasite infection. Birds have been demonstrated to affect predation, competition, human economic activity, and health. It was indicated that plants intrude on the ecosystem by competing with native species with their high-population density and capacity to multiply and cause allergic inducement. Interestingly, 300 species, including 25 mammals, 7 birds, 84 fishes, 28 amphibians, 22 reptiles, 1 insect, 32 spiders, 1 mollusk, 1 arthropod, and 99 plants, are included in the list of AAS. Conclusions: AAS designation plays a role in preventing the reduction of biodiversity by IAS in South Korea and preserving native species. Moreover, it is determined to provide considerable economic benefits by preventing socio-economic losses and ecological damage.

• Journal of the Korean Chemical Society
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• v.38 no.12
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• pp.891-897
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• 1994

A method has been investigated for the determination of Selenium in Ginseng radix, Ganoderma Lucidum and Garlic using hydride generation atomic absorption spectrometry (HG-AAS). The effects of several acids and sodium tetrahydroborate concentration and their flow rate on the determination of Selenium for the hydride generation were investigated. The method of sample decomposition was also investigated using various mineral acids, such as nitric, perchloric and sulfuric acid in the closed system and foreign ion effects were studied. In the optimum conditions, we obtained calibration curve in the range 0-40 ppb. The analytical data of Garlic, Ganoderma Lucidum and Ginseng radix are 289, 296, 198 ppb, respectively.

• Analytical Science and Technology
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• v.24 no.6
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• pp.443-450
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• 2011

Quantitative analytical condition for nickel in ceramic, metal and plastic materials using complexation and solvent extraction followed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and atomic absorption spectrophotometry (AAS) was studied. Ceramic, metal and plastic samples were dissolved by acid digestion. Nickel was determined by ICP-AES and AAS after extraction of Ni $(DMG)_2$ in $CHCl_3$. Recovery efficiency of nickel was satisfactory, and most of matrix elements causing interference could be effectively eliminated by the separation. Nickel in the certified reference materials (BAM-376 and PACS-2) were quantitatively determined without influence of sample matrix.

• International Journal of Concrete Structures and Materials
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• v.9 no.3
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• pp.283-294
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• 2015

In the present study, a porous concrete with alkali activated slag (AAS) and coal bottom ash was developed and the effect of carbonation on the physical property, microstructural characteristic, and heavy metal leaching behavior of the porous concrete were investigated. Independent variables, such as the type of the alkali activator and binder, the amount of paste, and $CO_2$ concentration, were considered. The experimental test results showed that the measured void ratio and compressive strength of the carbonated porous concrete exceeded minimum level stated in ACI 522 for general porous concrete. A new quantitative TG analysis for evaluating $CO_2$ uptake in AAS was proposed, and the result showed that the $CO_2$ uptake in AAS paste was approximately twice as high as that in OPC paste. The leached concentrations of heavy metals from carbonated porous concrete were below the relevant environmental criteria.